Safety device for valves of tank wagon bottoms

ABSTRACT

A safety device is provided for valves in tank bottoms, particularly in tank wagons. The device closes the valve automatically when there is a disturbance endangering the filling or the emptying procedure of the tank, particularly an improper shifting of the tank wagon. The device is particularly characterized by the provision of a hydraulic coupling element consisting of a piston and cylinder and located between the valve closing member and the valve actuating member. When the element is coupled its entire stroke producing volume is filled with a pressure medium. The element is connected with a reserve container and this connection is operated by a valve which in case of disturbance permits an escape of the pressure medium from the cylinder into the reserve container.

United States Patent Rudel 1541 SAFETY DEVICE FOR VALVES OF TANK WAGON BOTTOMS [72] 'lnventor: Kurt Rudel, Bremen, Germany [73] Assignee: Gustave F. Gerdts K.G., Breman,

Germany 22 Filed: Aug. 5, 1970 21 Appl. No.: 61,139

[30] Foreign Application Priority Data [451 Dec. 5, 1972 Primary Examiner-M. Cary Nelson Assistant ExaminerRichard Gerard Attorney-Richards and Geier [57] ABSTRACT A safety device is provided for valves in tank bottoms, particularly in tank wagons. The device closes the valve automatically when there is a disturbance endangering the filling or the emptying procedure of the tank, particularly an improper shifting of the tank wagon. The device is particularly characterized by the provision of a hydraulic coupling element consisting of a piston and cylinder and located between the valve closing member and the valve actuating member. When the element is coupled its entire stroke producing volume is filled with a pressure medium. The element is connected with a reserve container and this connection is operated by a valve which in case of disturbance permits an escape of the pressure medium 1 from the cylinder into the reserve container.

8 Claims, 1 Drawing Figure SAFETY DEVICE FOR VALVES OF TANK WAGON BOTTOMS DESCRIPTION OF THE INVENTION:

This invention relates to a safety device for valves in tank bottoms. The invention refers more particularly to a device of this type which automatically closes the bottom valve when there is a disturbance affecting the filling or the emptying procedure in the tank, particularly when an improper shifting'of the tank wagon takes place.

Existing safety devices of this type are so constructed that when a disturbance takes place they will act directly upon the drive causing it to assume a closing position and thus close the valve.

Since different systems are used as drives, such as hydraulic, pneumatic and mechanical drives, it was heretofore necessary to use different types of safety devices adapted to these individual drives. This has economic drawbacks, namely, expensive storage, high costs due to the small number of certain types of devices and their structures which are in part quite complicated. A further substantial drawback consists in the necessity of having different types of handling for the individual constructions. This often provides substantial difficulties for the operators and results in service errors which may endanger the operators and their surroundings, particularly if the filling consists of poisonous, explosive or corroding substances or the like. A further dangerous situation occurs since in many cases the operators simply give up the use of the safety device, since the bottom valve can be often operated without the safety device.

An object of the present invention is the provision of a safety device of the described type which will avoid the abovementioned drawbacks of prior art devices, which can be used for all drive systems and the use of which cannot be avoided.

Other objects of the present invention will become apparent in the course of the following specification.

In the accomplishment of the objectives of the present invention it was found desirable to provide a hydraulic coupling element consisting of a piston and a cylinder between the valve closing member and the valve actuating member, whereby when the element is coupled the entire stroke producing volume is filled with the pressure medium. The coupling element is connected with a reserve container and this connection is operated by a valve which permits the escape of the pressure medium from the cylinder into the reserve container in case of a disturbance.

The safety device of the present invention constituting a coupling member between the valve closing member and the valve actuating member, does not actively engage the drive, as is the case in prior art devices and, therefore, the type of the drive is of no importance any more for the use of this device. Consequently, one valve construction can be introduced into drives of all different types. Furthermore, since the safety device functions as a coupling it is absolutely necessary to switch it on in order to actuate the bottom valve.

In accordance with a further preferred embodiment of the present invention the cylinder of the coupling member is constructed as a sleeve having a cylindrical sack-like bore for the piston and sliding in a receptacle flanged between the valve casing and the casing of the valve drive. This is a simple construction particularly suitable for various types of valve constructions.

According to a further embodiment of the present invention the pressure medium can be supplied to the receptacle within the cylinder by providing channels in the receptacle as well as in the cylinder for the flow of the pressure medium to the cylinder. Furthermore, an annular space limited axially on both sides by packings is provided in the jacket surface of the cylinder. This space provides a connection between the channels of the cylinder and those of the receptacle throughout the entire sliding range of the cylinder. I

It is generally known that a primary danger occurring during the filling or the em'ptying of a tank wagon is an undesired shifting of the wagon. For this reason the present invention provides a rail hook for actuating the valve providing the connection between the coupling member and the reserve container. The hook actuates the safety device so as to separate it from the drive and the shut off device if an improper shifting takes place. This closes the bottom valve and prevents the outflow into the open of the contents of the boiler caused by damage to the outflow conduit resulting from this shiftmg.

The rail hook is well known in the art and is illustrated, for example, in German Gebrauchsmuster No. 1,838,241. It is used in tank wagons and it has a hookshaped end adapted to engage a rail. Its opposite end is usually connected with a cord which in the present construction is connected with the valve actuating the reserve container.

According to another feature of the present invention danger from fires is eliminated by providing a hose of a meltable or combustible material between the receptacle and the valve providing the connection between the coupling member and the reserve container.

Yet another advantageous embodiment of the present invention consists in that the receptacle with cylinder and piston, the shut off device and the reserve container for the pressure medium are all constructed as a single structural unit.

The invention will appear more clearly from the following detailed description when taken in connection with the accompanying drawing the sole FIGURE of which is a section through a safety device of the present invention.

The drawing shows a casing 1 of a bottom valve of a tank wagon having a valve spindle 2 and a casing 3 of a valve drive which is shown only diagrammatically. A set rod 4 can be actuated, for example, by hydraulic, pneumatic or mechanical means (not shown). A coupling member 5 is located between the casing l and the casing 3. The member 5 is connected by a conduit 6 of meltable or combustible material with a reserve container 7 for a pressure medium. A pilot valve 8 operates this connection. I

The coupling member 5 consists of a cylinder 9 with a sack-like cylindrical bore 10 and a piston 11 located therein. The cylinder 9 is operatively connected with the rod 4 and the piston 11 is operatively connected with the valve spindle 2. A spring 12 located within the cylinder 9 tends to push the piston 11 in the direction of the valve opening. Furthermore, the cylinder 9 slides in a receptacle l3 flanged between the valve casing 1 and the casing 3 of the drive. A stop 14 is used to limit the sliding movement of the casing 9 in the direction of the valve opening.

To provide an exchange of the pressure medium between the coupling member 5 and the reserve container 7, the connecting conduit 6 has one end attached into a channel of the receptacle 13 and another end attached into a bore hole 16 of the reserve container 7. The channel 15 opens into an annular space 17 extending around a cylindrical outer surface. A passage 18 in the casing 3 provides a connection between the space 17 and the cylindrical space 10. Packings 19 provided at opposite ends of the space 17 prevent the pressure medium from penetrating outwardly and being lost.

The bore hole 16 of the reserve container 7 is closed by the valve 8 which is provided with a spring 20 tending to open the valve. A lever 21 is used to close the valve. A rail hook (not shown) may be used to actuate the lever 21. The hook can be equally well replaced by a cord or the like, which will hold the valve 8 closed by means of the lever 21 and which will break or tip over in case of danger and thus will actuate the safety device from a distance;

The drawing 1 shows the safety device in the open position of the bottom valve. The entire actuating volume of the cylinder 9 is filled with the pressure medium and the valve 8 is closed by the rail hook. If the tank wagon is shifted and the connection with the rail hook is broken, the spring 20 will open the valve 8 and the pressure medium will escape from the cylinder 9 through the passage 18, the space 17, the channel 15, the conduit 6, the bore 16 and the space 22 in the reserve container 7. This frees the device for movement of the bottom valve in the closing direction responsive to the unbalanced forces acting on the closure member, so that the piston ll can be urged into the cylindrical space 10 until the closing position is reached.

To again open the bottom valve the drive 4 must be moved to the closing position. Then the spring 12 will move the cylinder 9 and the piston l 1 relatively to each other in such manner that the entire actuating volume is again filled with the pressure medium from the reserve container 7. After closing the valve 8, for example, by again applying the rail hook, the bottom valve can be opened again.

lclaim:

l. A safety device for valves of tank wagon bottoms, wherein the bottom valve unit comprises a valve closure member biased to the closed position and a valve actuating member, the safety device comprising a hydraulic coupling member operatively connected with said valve closure and said valve actuating members and having a cylinder and a piston, said cylinder having an inner space containing said piston and adapted to be filled with a fluid pressure medium to provide a force transmitting medium between said closure and actuating members, a reserve container, a conduit between said reserve container and said coupling member, a pilot valve controlling fluid flow in said conduit and means releasably holding said pilot valve in a closed position, said pilot valve being biased to an open position such that the pressurized condition in said coupling member is relieved, said means being res onsive to a movement of the bottom valve unit as a w ole to release said pilot valve and thereby relieve said pressure medium and effect closing of the valve closure member independently of the actuating member.

2. A safety device in accordance with claim 1, wherein said valve closure member has a casing, wherein said valve actuating member has a casing, and said hydraulic coupling member comprising a flanged receptacle between said two casings, said cylinder being slidably mounted within said receptacle.

3. A safety device in accordance with claim 2, wherein said receptacle and said cylinder have passages, said receptacle further having an annular space communicating with said passages and enclosing said cylinder, whereby saidpassages communicate with the interior of said cylinder, said annular space extending axially along the entire sliding stroke of said cylinder, and packing rings located at opposite ends of said space.

4. A safety device in accordance with claim 2, wherein said receptacle, said cylinder, said piston, said reserve conduit and the last-mentioned valve all constitute a single unit.

5. A safety device in accordance with claim 1, comprising a spring located within said cylinder and pressing said piston in a direction corresponding to the opening of the valve closure member.

6. A safety device in accordance with claim 1 wherein the bias for said pilot valve comprises a spring engaging said pilot valve and tending to open the pilot valve.

7. A safety device in accordance with claim 1, wherein said pilot valve is adapted to be connected to a rail hook for actuating said pilot valve.

8. A safety device in accordance with claim I, wherein said conduit consists of a meltable or combustible material. 

1. A safety device for valves of tank wagon bottoms, wherein the bottom valve unit comprises a valve closure member biased to the closed position and a valve actuating member, the safety device comprising a hydraulic coupling member operatively connected with said valve closure and said valve actuating members and having a cylinder and a piston, said cylinder having an inner space containing said piston and adapted to be filled with a fluid pressure medium to provide a force transmitting medium between said closure and actuating members, a reserve container, a conduit between said reserve container and said coupling member, a pilot valve controlling fluid flow in said conduit and means releasably holding said pilot valve in a closed position, said pilot valve being biased to an open position such that the pressurized condition in said coupling member is relieved, said means being responsive to a movement of the bottom valve unit as a whole to release said pilot valve and thereby relieve said pressure medium and effect closing of the valve closure member independently of the actuating member.
 2. A safety device in accordance with claim 1, wherein said valve closure member has a casing, wherein said valve actuating member has a casing, and said hydraulic coupling member comprising a flanged receptacle between said two casings, said cylinder being slidably mounted within said receptacle.
 3. A safety device in accordance with claim 2, wherein said receptacle and said cylinder have passages, said receptacle further having an annular space communicating with said passages and enclosing said cylinder, whereby said passages communicate with the interior of said cylinder, said annular sPace extending axially along the entire sliding stroke of said cylinder, and packing rings located at opposite ends of said space.
 4. A safety device in accordance with claim 2, wherein said receptacle, said cylinder, said piston, said reserve conduit and the last-mentioned valve all constitute a single unit.
 5. A safety device in accordance with claim 1, comprising a spring located within said cylinder and pressing said piston in a direction corresponding to the opening of the valve closure member.
 6. A safety device in accordance with claim 1 wherein the bias for said pilot valve comprises a spring engaging said pilot valve and tending to open the pilot valve.
 7. A safety device in accordance with claim 1, wherein said pilot valve is adapted to be connected to a rail hook for actuating said pilot valve.
 8. A safety device in accordance with claim 1, wherein said conduit consists of a meltable or combustible material. 